When using hints?

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Poston Wed, 05 Jul 2006 2:41 pm

When should I use hints? Could someone explain to me when should I use USE_HASH, USE_MERGE, FULL, INDEX, USE_MERGE and etc.

Thanks, Everton
Location: Brasilia-DF

Everton Sims

Poston Fri, 28 Jul 2006 2:49 pm

Everton, Our good old Thomas Kyte said that when a query needs to hint, or she's bad writing or bad system modeled.

The hints you questions are as below: USE_HASH tell Oracle to give preference to join as HASH_JOIN USE_MERGE-tell Oracle to give preference to join as FULL-MERGE_JOIN tell Oracle to do full scan the tables INDEX-tell Oracle to use one or more indexes from one or more tables.

But returning to the hints, take a look at: http://www.psoug.org/reference/hints.html Or so on pages from Oracle, searching, of course.

Abs, Gustavo.
Location: Niterói - RJ

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